Signaling compression information using routing protocols

TECHNICAL FIELD

The present disclosure relates generally to networks, and more particularly to routing protocols used by networks.

BACKGROUND

Businesses, universities, and other entities typically deploy networks within their organization, to assist in the transfer of data and for communications purposes such as e-mail. The efficacy of such internal networks, which may include local area networks (LANs) that are primarily located in one geographic location, as well as wide area networks (WANs) that may be spread across a number of geographic locations, are obviously improved by being connected to still other networks, such as the Internet, as well as each other. One configuration for connecting, for example, a WAN for a company's New York City office to a WAN for the same company's Los Angeles office, is to connect the two WANs to a so-called provider network. The routers that connect the WANs with the provider network are commonly referred to as edge routers. Those on the company-owned WAN side of the network are called customer edge routers, while those on the provider-owned side of the network are known as provider edge routers. Communications from the New York City office WAN thus travel from a node on that WAN to a customer edge router, than to a provider edge router on one side of the provider network, over the provider network to a provider edge router on the other side of the provider network, and then to a customer edge router in the Los Angeles office WAN, and finally to the destination node on the Los Angeles office WAN. Depending on the size of the networks, vast amounts of data may thus be communicated between WANs.

Numerous types of wide area network (WAN) accelerators have been defined to help customer edge routers (CEs) achieve maximum throughput out of their WAN links. WAN accelerators require the use of proprietary mechanisms or manual configuration by an operator of all endpoints to achieve the desired throughput by selecting the same compression technique to be used by the accelerator. By compressing the data, customer edge routers are able to send more data over the same amount of bandwidth compared with uncompressed data, which takes up more networking resources. Thus, network performance may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

<figref idref="DRAWINGS">FIG. 1</figref> illustrates an example router architecture for a customer edge router according to one embodiment disclosed herein.

<figref idref="DRAWINGS">FIG. 2</figref> illustrates an example network including customer edge routers as depicted in <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 3</figref> illustrates a flowchart of a procedure preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when signaling compression information through a routing protocol.

<figref idref="DRAWINGS">FIG. 4</figref> illustrates a flowchart of a procedure preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when selecting a compression technique signaled through a routing protocol.

<figref idref="DRAWINGS">FIG. 5</figref> illustrates a flowchart of a procedure preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when signaling compression information through a routing protocol by transmitting compression information.

<figref idref="DRAWINGS">FIG. 6</figref> illustrates a flowchart of a procedure performed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when selected a compression technique signaled through a routing protocol.

<figref idref="DRAWINGS">FIGS. 7-10</figref> illustrate flowcharts of procedures preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when a matched compression technique signaled through a routing protocol is no longer being used, and a new compression technique must be signaled, with the same or another customer edge router.

<figref idref="DRAWINGS">FIG. 11</figref> illustrates a flowchart of a procedure preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when the routing protocol used between provider edge routers differs from the routing protocol used between a customer edge router and a provider edge router.

<figref idref="DRAWINGS">FIG. 12</figref> illustrates a flowchart of a procedure preformed by the customer edge router depicted in <figref idref="DRAWINGS">FIG. 1</figref> when acting only on a class of packets that is identified through a routing protocol.

<figref idref="DRAWINGS">FIG. 13</figref> illustrates an example structure of a Border Gateway Protocol (BGP) Compression Capability as described herein.

<figref idref="DRAWINGS">FIG. 14</figref> illustrates an example structure of a Compression Algorithms Supported Type Length Value (CAS-TLV) as described herein.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Overview

In an embodiment there is provided a method of signaling compression information between customer edge routers in a network. The method includes announcing (for example, transmitting an announcement) an ability to compress packets. The ability is represented by an addition to a routing protocol packet. As an example, the customer edge router may include additional announcement information in a packet that indicates this ability. The announcement may be transmitted from a customer edge router to other customer edge routers. The method also includes receiving an announcement of an ability to compress packets from another customer edge router in the network. The announcement is represented by an addition to a routing protocol packet. Examples of these additions are described in greater detail below with respect to particular routing protocols. The customer edge router then matches a compression technique with another customer edge router. The method includes receiving compression information from the another customer edge router in a routing protocol packet. The compression information may identify, for example, a particular compression technique that the another customer edge router is capable of using. The method then includes determining that the compression technique identified in the compression information matches any compression technique the customer edge router is programmed to use. Packets transmitted from and received by the customer edge router are flagged to be compressed and decompressed according to the matched compression technique.

In a related embodiment, receiving may include receiving compression information from the another customer edge router in a routing protocol packet, wherein the compression information identifies a plurality of compression techniques, and determining may include determining that any two or more of the identified plurality of compression techniques match any compression techniques the customer edge router is programmed to use; and selecting a matched compression technique from any of the matched compression techniques.

In another related embodiment, matching may include transmitting compression information to the another customer edge router in a routing protocol packet, wherein the compression information identifies a compression technique, and wherein the another customer edge router receives the routing protocol packet and determines that a compression technique identified in the compression information of the routing protocol packet matches any compression technique the another customer edge router is programmed to use.

In a further related embodiment, transmitting may include transmitting compression information to the another customer edge router in a routing protocol packet, wherein the compression information identifies a plurality of compression techniques, and wherein the another customer edge router receives the routing protocol packet, determines that any of the plurality of compression techniques identified in the compression information of the routing protocol packet matches any compression technique the another customer edge router is programmed to use, and selects a matched compression technique from any of the matched compression techniques.

In another further related embodiment, the method may include receiving a message from the another customer edge router indicating that a change in compression techniques is needed; identifying a new matched compression technique with the another customer edge router by repeating the step of matching; and flagging packets transmitted from and received by the customer edge router to be compressed and decompressed according to the identified new matched compression technique.

In still another further related embodiment, the method may include failing to identify a new matching compression technique; in response, locating a second customer edge router with an announced capability to compress packets, wherein the second customer edge router and the another customer edge router are connected to the same local network; conducting a new matching with the second customer edge router by repeating the step of matching; and flagging packets transmitted from and received by the customer edge router to be compressed and decompressed according to the matched compression technique.

In another related embodiment, the method may include determining that the customer edge router is no longer able to use the matched compression technique; in response, sending the another customer edge router a message indicating that a change in compression techniques is needed; identifying a new matched compression technique with the another customer edge router by repeating the step of matching; and flagging packets transmitted from and received by the customer edge router to be compressed and decompressed according to the identified new matched compression technique. In a further related embodiment, the method may include failing to identify a new matching compression technique; in response, locating a second customer edge router with an announced capability to compress packets, wherein the second customer edge router and the another customer edge router are connected to the same local network; conducting a new matching with the second customer edge router by repeating the step of matching; and flagging packets transmitted from and received by the customer edge router to be compressed and decompressed according to the matched compression technique.

In another related embodiment, wherein the customer edge router communicates with other customer edge routers through a provider edge router and a provider network, the method may include detecting a customer edge-provider edge routing protocol used for transmissions between the customer edge router and a corresponding provider edge router; and if the detected customer edge-provider edge routing protocol differs from a provider edge-provider edge routing protocol used for transmissions between provider edge routers, extending any compression information from the customer edge-provider edge routing protocol for use by the provider edge-provider edge routing protocol and extracting any compression information from the provider edge-provider edge routing protocol for use by the customer edge-provider edge routing protocol.

In still another related embodiment, wherein compression information identifies a compression technique and a class of packets to which the compression technique is to be applied, flagging may include, upon completion of the negotiation, flagging packets transmitted from and received by the customer edge router, that are in the identified class of packets, to be compressed and decompressed according to the matched compression technique.

Arrangements of the invention involving a computer program product are typically provided as software, code and/or other data structures arranged or encoded on a computer readable medium such as an optical medium (e.g., CD-ROM), floppy or hard disk or other a medium such as firmware or microcode in one or more ROM or RAM or PROM chips or as an Application Specific Integrated Circuit (ASIC) or as downloadable software images in one or more modules, shared libraries, etc. The software or firmware or other such configurations may be installed onto a computerized device to cause one or more processors in the computerized device to perform the techniques explained herein as embodiments of the invention. Software processes that operate in a collection of computerized devices, such as in a group of data communications devices or other entities may also provide the system of the invention. The system of the invention may be distributed between many software processes on several data communications devices, or all processes could run on a small set of dedicated computers, or on one computer alone. It is to be understood that the embodiments of the invention may be embodied strictly as a software program, as software and hardware, or as hardware and/or circuitry alone, such as within a data communications device. The features of the invention, as explained herein, may be employed in data communications devices and/or software systems for such devices such as those manufactured by Cisco Systems, Inc. of San Jose, Calif.

DETAILED DESCRIPTION

Embodiments of the invention describe a mechanism to carry compression information along with other routing information between different customer edge routers of any given enterprise. Though embodiments described herein reference customer edge routers, those skilled in the art will recognize that embodiments may easily be extended into much broader spaces where compression is used, such as for mobile phones that access a network via General Packet Radio Service (GPRS) or Wireless Access Protocol (WAP).

Embodiments of the invention describe how to create and exchange compression information between customer edge routers and thereby allow customer edge routers to compress traffic and optimize their Wide Area Network (WAN) links whenever forwarding their data to the destinations supporting such a mechanism. With the compression information exchanged between customer edge routers, each of the customer edge routers would know at the route level which compression algorithm to apply. This allows customer edge routers to compress the data going towards their virtual private network (VPN) sites or to any destinations that have announced compression support that corresponds to the type of compression the customer edge router itself supports. Thus, compressing data over WAN links may result in better throughput of the WAN links, at least two times the data obtained from using the PPP compression algorithm, which may easily be incorporated into embodiments described herein. Further, automatic signaling allows Internet Service Providers (ISPs) to sell this as a service for their managed customer edge routers, and there is no or very little configuration support without risking black-holing data.

In one embodiment, a new Border Gateway Protocol (BGP) capability, known as BGP Compression Capability, and a new BGP attribute, known as BGP Compression Attribute, are defined. BGP speakers announce a BGP Compression Attribute to the speakers that support the BGP Compression Capability. The BGP Compression Attribute carries compression algorithm information about the originating speaker. The details of the BGP Compression Capability, Attribute and its operation are described in greater detail below. In an alternate embodiment, a new Type-Length-Value (TLV) is defined for the Open Shortest Path First (OSPF) protocol. This new TLV is known as a Compression Algorithms Supported Type Length Value (CAS-TLV) and is added to at least OSPF Hello packets. Similar to the BGP Compression Capability and BGP Compression Attribute, the CAS-TLV identifies both an ability to compress as well as compression information about an originating speaker.

More particularly, <figref idref="DRAWINGS">FIG. 1</figref> is a block diagram illustrating an example architecture of a customer edge router <b>110</b> that executes, runs, interprets, operates or otherwise performs a compression signaling application <b>140</b>-<b>1</b> and a compression signaling process <b>140</b>-<b>2</b> suitable for use in explaining example configurations disclosed herein. As shown in this example, the customer edge router <b>110</b> includes an interconnection mechanism <b>111</b> such as a data bus or other circuitry that couples a memory system <b>112</b>, a processor <b>113</b>, a public communications interface <b>115</b> and a private communications interface <b>11</b><b>7</b>. The public communications interface <b>115</b> and the private communications interface <b>117</b> enable the customer edge router <b>110</b> to communicate with other networks (such as the networks <b>120</b>, <b>130</b>, and <b>150</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>) and with other customer edge routers (such as another customer edge router <b>140</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>). An example network configuration including the customer edge router <b>110</b> is shown in greater detail in <figref idref="DRAWINGS">FIG. 2</figref>, and is described further below.

The memory system <b>112</b> is any type of computer readable medium and in this example is encoded with a compression signaling application <b>140</b>-<b>1</b> that includes a compression signaling process <b>140</b>-<b>2</b>. The compression signaling application <b>140</b>-<b>1</b> may be embodied as software code such as data and/or logic instructions (e.g., code stored in the memory system <b>112</b> or on another computer readable medium such as a removable disk) that supports processing functionality according to different embodiments described herein. During operation of the customer edge router <b>110</b>, the processor <b>113</b> accesses the memory system <b>112</b> via the interconnection mechanism <b>111</b> in order to launch, run, execute, interpret or otherwise perform the logic instructions of the compression signaling application <b>140</b>-<b>1</b>. Execution of the compression signaling application <b>140</b>-<b>1</b> in this manner produces processing functionality in a compression signaling process <b>140</b>-<b>2</b>. In other words, the compression signaling process <b>140</b>-<b>2</b> represents one or more portions or runtime instances of the compression signaling application <b>140</b>-<b>1</b> performing or executing within or upon the processor <b>113</b> in the customer edge router <b>110</b> at runtime.

It is noted that example configurations disclosed herein include the compression signaling application <b>140</b>-<b>1</b> itself including the compression signaling process <b>140</b>-<b>2</b> (i.e., in the form of un-executed or non-performing logic instructions and/or data). The compression signaling application <b>140</b>-<b>1</b> may be stored on a computer readable medium (such as a floppy disk), hard disk, electronic, magnetic, optical or other computer readable medium. The compression signaling application <b>140</b>-<b>1</b> may also be stored in a memory system <b>112</b> such as in firmware, read only memory (ROM), or, as in this example, as executable code in, for example, Random Access Memory (RAM). In addition to these embodiments, it should also be noted that other embodiments herein include the execution of the compression signaling application <b>140</b>-<b>1</b> in the processor <b>113</b> as the compression signaling process <b>140</b>-<b>2</b>. Those skilled in the art will understand that the customer edge router <b>110</b> may include other processes and/or software and hardware components, such as an operating system not shown in this example.

<figref idref="DRAWINGS">FIG. 2</figref> illustrates an example configuration of a network that may employ a customer edge router, such as the customer edge router <b>110</b> described above in regards to <figref idref="DRAWINGS">FIG. 1</figref>. The customer edge router <b>110</b> is connected to a private network <b>201</b>, which may be but is not limited to a local area network (LAN) of a company's New York City office. The customer edge router <b>110</b> is also connected to a provider edge router <b>210</b>. The provider edge router <b>210</b> is, in turn, connected to a network <b>202</b>, which may be a network that is particular to the provider, or may be a public network such as the public Internet. Another customer edge router <b>140</b>, which may be connected to a network <b>203</b>, such as but not limited to a LAN of the same company's Los Angeles office for example, is also needed. The another customer edge router <b>140</b> is also connected to a provider edge router <b>210</b>, which in turn is connected to the network <b>202</b>. Traffic going back and forth between the New York City office's LAN <b>201</b> and the Los Angeles office's LAN <b>203</b> must first travel over the respective customer edge routers <b>110</b> and <b>140</b> and their respective provider edge routers <b>210</b>, as well as the network <b>203</b>. Various routing protocols, such as Border Gateway Protocol (BGP) and Open Shortest Path First (OSPF), as well as other proprietary protocols, may be used to handle routing along the described network path. Note that the exact configuration of a network including one or more customer edge routers <b>110</b> may differ from that shown in <figref idref="DRAWINGS">FIG. 2</figref>, which is provided solely as an example.

A number of flowcharts of the presently disclosed method are illustrated in <figref idref="DRAWINGS">FIGS. 3-12</figref>. The rectangular elements are herein denoted “processing blocks” and represent computer software instructions or groups of instructions. Alternatively, the processing blocks represent steps performed by functionally equivalent circuits such as a digital signal processor circuit or an application specific integrated circuit (ASIC). The flowcharts do not depict the syntax of any particular programming language. Rather, the flowcharts illustrate the functional information one of ordinary skill in the art requires to fabricate circuits or to generate computer software to perform the processing required in accordance with the present invention. It should be noted that many routine program elements, such as initialization of loops and variables and the use of temporary variables are not shown. It will be appreciated by those of ordinary skill in the art that unless otherwise indicated herein, the particular sequence of steps described is illustrative only and may be varied without departing from the spirit of the invention. Thus, unless otherwise stated, the steps described below are unordered, meaning that, when possible, the steps may be performed in any convenient or desirable order. More specifically, <figref idref="DRAWINGS">FIGS. 3-12</figref> illustrate flowcharts of various embodiments as performed by the compression signaling application <b>140</b>-<b>1</b> when executing as the compression signaling process <b>140</b>-<b>2</b>.

In <figref idref="DRAWINGS">FIG. 3</figref>, a customer edge router, such as the customer edge router <b>110</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>, signals compression information to another customer edge router, such as the another customer edge router <b>140</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>. The compression signaling application <b>140</b>-<b>1</b>, executing as the compression signaling process <b>140</b>-<b>2</b>, allows the customer edge router <b>110</b> to announce, to other customer edge routers, an ability to compress packets, step <b>301</b>. The ability to compress packets is announced by adding data to a routing protocol packet, such that the ability is represented by the added data. For example, if the routing protocol used by the customer edge router <b>110</b> to communicate with a corresponding provider edge router, and ultimately with the another customer edge router <b>140</b>, is Border Gateway Protocol (BGP), than the compression signaling process <b>140</b>-<b>2</b> adds data known as a BGP Compression Capability (BGP-CAP) to a BGP packet. The compression signaling process <b>140</b>-<b>2</b> may add the BGP Compression Capability to a BGP packet if the customer edge router <b>110</b> is willing to receive compressed packets from another customer edge router, or if the customer edge router <b>110</b> would like to send compressed packets to another customer edge router.

The BGP Compression Capability is defined as follows, with an example structure shown in <figref idref="DRAWINGS">FIG. 13</figref>. The capability code is an identifier for the data. In an embodiment, this identifier is assigned by Internet Assigned Numbers Authority. In an embodiment, the length of the capability is variable, and the capability value may be one or more of the following: an Address Family Identifier (AFI) or a Subsequent Address Family Identifier (SAFI). The AFI field carries the identity of the network layer protocol associated with the network address that follows. Presently defined values for the AFI field are specified in RFC <b>1700</b>, which defines various parameters (i.e., numerical and alphabetical values) used in protocols. The SAFI field provides additional information about the type of the network layer reachability information carried in the compression information that is sent as described below.

Alternatively, if the customer edge router <b>110</b> uses Open Shortest Path First (OSPF) to communicate with a provider edge router, the compression signaling process <b>140</b>-<b>2</b> will add a Compression Algorithms Supported Type Length Value (CAS-TLV) to an OSPF packet. This is a particular type of TLV added to an OSPF packets, an example of which is defined here. However, the same functionality may be achieved by using a TLV with a different name, structure, or both. The CAS-TLV is defined in the link-local signaling [LLS] block of Hello packets, and an example structure of the CAS-TLV is shown in <figref idref="DRAWINGS">FIG. 14</figref>. The type field may be either from a private number space, or if standardized a later time, may be allocated from the Internet Assigned Numbers Authority (IANA) assigned number space. The length of the CAS-TLV is four octets. The CAS-TLV also includes compression information, as is described in greater detail below.

Other routing protocols, such as proprietary routing protocols created and used by Cisco Systems, Inc. and other companies, may be similarly modified to transmit an announcement of an ability to compress data and to identify techniques to compress data. Such modifications may depend on the particulars of the routing protocols, and may be performed with ease by one of ordinary skill in the art. Example descriptions given below with respect to BGP and OSPF are meant solely as examples, and are not limiting in any way.

The customer edge router <b>110</b>, through the compression signaling process <b>140</b>-<b>2</b>, then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>302</b>. As with the ability announced by the customer edge router <b>110</b>, the received announcement is also represented by an addition to a routing protocol packet, such as those described above. In the case of BGP, the received announcement must contain the Compression Capability described above, or the customer edge router <b>110</b> will not transmit compressed packets or receive compressed packets from the another customer edge router. Similarly, in the case of OSPF, the received announcement must contain the CAS-TLV in the received Hello packet, or else data transmitted between that customer edge router and the customer edge router <b>110</b> will not be compressed. It is possible for a customer edge router to decide, while in the course of transmitting and received compressed packets, to no longer do so. In this situation, the compression signaling process <b>140</b>-<b>2</b> of that customer edge router may remove the CAS-TLV from its Hello packets, for OSPF, or cease announcing the BGP Compression Capability, for BGP, or otherwise communicate the decision, as described in greater detail below.

Further, any number of customer edge routers may announce an ability to compress packets, and similarly, any number of announcements of an ability to compress packets may be received by a single customer edge router. For example, each local area network of a particular office of a company may have a plurality of customer edge routers. All of the plurality of customer edge routers, or any subset of the plurality, may choose to send announcements to some subset, or all, of a plurality of customer edge routers located at the edge of a local area network of another office for the same company. Each customer edge router that receives multiple announcements will need to select a corresponding other customer edge router before proceeding to attempt to match the type of compression that will be used for transmission of packets between those customer edge routers.

The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt to match with, step <b>303</b>. There are two scenarios for how this matching will occur, one of which is illustrated by the flowchart shown in <figref idref="DRAWINGS">FIG. 3</figref>. The other scenario is illustrated in the flowchart shown in <figref idref="DRAWINGS">FIG. 5</figref>, and is discussed in greater detail below. The two scenarios are based on whether the customer edge router <b>110</b> or the another customer edge router initiates the matching through its compression signaling process <b>140</b>-<b>2</b>.

In the situation where the another customer edge router initiates the matching process, the compression signaling process <b>140</b>-<b>2</b> performs as follows (as shown in <figref idref="DRAWINGS">FIG. 3</figref>). First, the compression signaling process <b>140</b>-<b>2</b> receives compression information from the another customer edge router in a routing protocol packet, step <b>304</b>. Then, the compression signaling process <b>140</b>-<b>2</b> determines that the compression technique identified in the compression information matches any compression technique the customer edge router is programmed to use, step <b>305</b>.

A compression technique, as described above, may be any type of compression algorithm that a customer edge router, such as the customer edge router <b>110</b>, is able to use to compress and decompress data. Depending on the type of routing protocol used, the compression information may vary in form, but will always identity at least one compression technique. For example, in one embodiment, for BGP, the compression information takes the form of a new BGP attribute called the BGP Compression attribute. In one embodiment, this attribute may include a transitive optional BGP path attribute, with a particular Type Code, such as but not limited to XXXX. The BGP Compression attribute may have a fixed length of 4 octets. Each bit in an octet may represent a well-known type of compression algorithm defined. In one embodiment, the value types are defined as follows: 0x00000000-0x0000ffff, which requires Internet Assigned Numbers Authority allocation; 0x0000ffff-0xffffffff, which is private allocation space that may be used, for example but not limited to, in any way according to the needs of the user; 1 IP Compression Protocol (described in detail in RFC 3545); 2 IP Payload Compression Protocol (described in detail in RFC 3173); 4 IP Payload Compression Using LZS (described in detail in RFC 2395). Of course, this allocation is merely one of many ways in which compression algorithms may be identified. Any allocation is possible, as long as the allocation is usable by BGP. Further, other compression algorithms may be included in the allocation.

To perform the match, the compression signaling process <b>140</b>-<b>2</b> for the initiating customer edge router announces, for example, the above-defined BGP Compression attribute to the other customer edge router that also announced an ability to compress packets. As the attribute is optionally transitive, any router that uses BGP and receives such an attribute is forced to silently forward it to its neighbors. Upon receiving the BGP Compression attribute, the other customer edge router tries to match the received Compression algorithms defined/set in the BGP Compression attribute with the compression technique(s)/algorithm(s) it is able to support. If the match results in a no-match, then the compression attribute is silently ignored. If the match returns with a successful match, the another customer edge router installs that compression technique along with the route in the forwarding information base (FIB)/Cisco Express Forwarding (CEF) table.

Alternatively, if the routing protocol used is OSPF, the CAS-TLV transmitted by the compression signaling process <b>140</b>-<b>2</b> will define the compression algorithm(s)/technique(s) supported by the initiating customer edge router, in a bitfield of, for example, four octets. Each bit may represent a well-known compression algorithm. Such compression algorithms may include those described above with regards to BGP, and similarly, any identified compression algorithms may be allocated as described above with regards to BGP or in any other way that is compatible with OSPF. OSPF will send a CAS-TLV in Hello packets, which helps in capability discovery among peers (i.e., other customer edge routers). If the CAS-TLV is not present, the compression signaling process <b>140</b>-<b>2</b> presumes that the peer does not support any compression algorithms. As further packets are transmitted over time, the compression signaling process will monitor the TLV to determine whether it has changed in any way. If the TLV has not changed, the compression signaling process <b>140</b>-<b>2</b> takes no action. However, if at any point the CAS-TLV has changed, which includes situations where the CAS-TLV was not present before, or was present before but is not present now, the compression signaling process <b>140</b>-<b>2</b> attempts to determine a common compression algorithm. A preference may be given to keep using the current compression algorithm, if possible. If the compression signaling process <b>140</b>-<b>2</b> selects a compression algorithm that is different than the one in use before, including situations when there was no prior compression, or there was compression but no compression is needed now, a routing table update is triggered. The route update will cause the compression signaling process <b>140</b>-<b>2</b> to re-install all routes via this peer (customer edge router) with the appropriate algorithm information.

Finally, once a match is determined, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the matched compression technique, step <b>306</b>. Thus, whenever a customer edge router announces its site's routes via routing protocols such as but not limited to BGP/OSPF/EIGRP, the customer edge router may set a compression bit in a routing table on those routes that belong to its own site. For example, when BGP is the routing protocol used between a provider edge router and a customer edge router, a compression bit is set in the routing table (or its equivalent) on all the Interior Gateway Protocol (IGP) routes that are redistributed into BGP. BGP would provide a handler to modify all such IGP routes in the forwarding information base (FIB) of the customer edge router with a bit that signals the FIB to perform de-compression on a per route basis. That way, any received traffic that is compressed may be signaled to be de-compressed on a per route basis at the customer edge router and then forwarded as native traffic. A similar mechanism may be extended for OSPF and other Interior Gateway Protocols where internal routes in a routing table may be modified with a bit that signals a FIB to perform de-compression on a per route basis.

With routes marked in a routing table with compressed and decompressed bits, any data traffic may be compressed and decompressed with the information provided by routing protocols. Data packets are compressed whenever the routes in FIB (or routing table or other equivalent structure) are marked with the compress bits and are uncompressed at the incoming customer edge router where the routes are marked with uncompress bits. All the data packets that are received uncompressed may be forwarded straight as native packets without performing de-compression.

In <figref idref="DRAWINGS">FIG. 4</figref>, the compression signaling process <b>140</b>-<b>2</b> selects a particular compression technique that is signaled through a routing protocol. In other words, when a customer edge router announces an ability to compression data through a routing protocol packet, the customer edge router also identifies a number of different compression techniques that it is able to use to compress data. When two customer edge routers match a compression technique, one is selected from the available number of techniques.

Through its compression signaling process <b>140</b>-<b>2</b>, the customer edge router <b>110</b> announces an ability to compress packets, step <b>401</b>, to other customer edge routers. As described above, the ability to compress packets is announced by adding data to a routing protocol packet, where the added data represents the ability. The customer edge router <b>110</b> (i.e., its compression signaling process <b>140</b>-<b>2</b>) then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>402</b>. As with the ability announced by the customer edge router <b>110</b>, the received announcement is also represented by an addition to a routing protocol packet, such as those described above.

The compression signaling process <b>140</b>-<b>2</b> of the customer edge router <b>110</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt a match with, step <b>403</b>. The way in which the compression signaling process <b>140</b>-<b>2</b> matches a compression technique depends on whether the customer edge router <b>110</b> receives or transmits compression information through its compression signaling process <b>140</b>-<b>2</b>. The second situation (i.e., the customer edge router <b>110</b> transmits compression information) is described in greater detail with regards to <figref idref="DRAWINGS">FIG. 6</figref> below. The first situation requires that the customer edge router <b>110</b> receives compression information from the another customer edge router in a routing protocol packet, step <b>404</b>. The compression information received from the another customer edge router identifies a plurality of compression techniques, step <b>407</b>. The plurality of compression techniques, in an example embodiment, include IP Compression Protocol (described in detail in RFC 3545), IP Payload Compression Protocol (described in detail in RFC 3173), and IP Payload Compression Using LZS (described in detail in RFC 2395). Of course, other compression techniques, such as but not limited to proprietary or other public compression techniques, may also be used. The compression signaling process <b>140</b>-<b>2</b> then determines, step <b>405</b>, that any two or more of the identified plurality of compression techniques match any compression techniques the customer edge router is programmed to use, step <b>408</b>. The compression signaling process <b>140</b>-<b>2</b> selects a matched compression technique from any of the matched compression techniques, step <b>409</b>. As described above, the plurality of compression techniques may include any type of compression algorithm that a customer edge router, such as the customer edge router <b>110</b>, is able to use to compress (and decompress) data. Finally, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the selected matched compression technique, step <b>406</b>. In this way, customer edge routers are not limited to a single compression technique when transmitting and receiving data from other customer edge routers, creating greater flexibility and potentially increased security.

<figref idref="DRAWINGS">FIGS. 5 and 6</figref> show how the customer edge router <b>110</b> signals compression information through a routing protocol when the compression signaling process <b>140</b>-<b>2</b> of the customer edge router <b>110</b> transmits the compression information, instead of receiving it (which is described in connection with <figref idref="DRAWINGS">FIGS. 3 and 4</figref>). <figref idref="DRAWINGS">FIG. 5</figref> correlates to <figref idref="DRAWINGS">FIG. 3</figref>, in that the matching of a single compression technique is described. <figref idref="DRAWINGS">FIG. 6</figref> correlates to <figref idref="DRAWINGS">FIG. 4</figref>, in that the selection of a single compression technique, from among the matching of at least two compression techniques, is detailed.

The initial steps shown in <figref idref="DRAWINGS">FIG. 5</figref> are thus the same as described above with regards to <figref idref="DRAWINGS">FIG. 3</figref>. In other words, in <figref idref="DRAWINGS">FIG. 5</figref>, the compression signaling process <b>140</b>-<b>2</b> allows the customer edge router <b>110</b> to announce, to other customer edge routers, an ability to compress packets, step <b>501</b>. The ability to compress packets is announced by adding data to a routing protocol packet, such that the added data represents the ability. The compression signaling process <b>140</b>-<b>2</b> of the customer edge router <b>110</b> then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>502</b>. The received announcement is also represented by an addition to a routing protocol packet, such as those described above. The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt to match with, step <b>503</b>. It is at this point that <figref idref="DRAWINGS">FIG. 5</figref> diverges from the path described above in regards to <figref idref="DRAWINGS">FIG. 3</figref>.

With respect to <figref idref="DRAWINGS">FIG. 5</figref>, the second scenario referred to above in the discussion of <figref idref="DRAWINGS">FIG. 3</figref> will be described. That is, the customer edge router <b>110</b> initiates the matching through its compression signaling process <b>140</b>-<b>2</b>, instead of receiving compression information from another customer edge router. In contrast, here the compression signaling process <b>140</b>-<b>2</b> transmits compression information to the another customer edge router in a routing protocol packet, step <b>504</b>. As before, the compression information identifies a compression technique. The compression information may identify a plurality of compression techniques (see description of <figref idref="DRAWINGS">FIG. 4</figref> above and <figref idref="DRAWINGS">FIG. 6</figref> below), but for this purpose, it is sufficient that the compression information identifies only one compression technique. The identified compression technique may be any of those listed above, or another compression technique not mentioned herein.

After the customer edge router <b>110</b> transmits compression information in a routing protocol packet, the another customer edge router receives the routing protocol packet. The another customer edge router will then determine that a compression technique identified in the compression information of the routing protocol packet matches any compression technique the another customer edge router is programmed to use. In other words, the another customer edge router and its own compression signaling process <b>140</b>-<b>2</b> perform the same steps when receiving compression information in a routing protocol packet as the customer edge router <b>110</b> does when it receives compression information (i.e., these steps are described above with regards to <figref idref="DRAWINGS">FIG. 3</figref>).

Finally, once a match is determined, the compression signaling process <b>140</b>-<b>2</b> of the customer edge router <b>110</b> flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the matched compression technique, step <b>506</b>. The customer edge router <b>110</b> (i.e., its compression signaling process <b>140</b>-<b>2</b>) knows the matched compression technique by receiving compressed data from an another customer edge router that the customer edge router <b>110</b> transmitted compression information to. The customer edge router <b>110</b>, of course, knows the types of compression techniques it is capable of using, and what technique the compression signaling process <b>140</b>-<b>2</b> identified when the process <b>140</b>-<b>2</b> transmitted compression information. Thus, upon the initial receipt of a compressed packet, the customer edge router knows it must be compressed according to a compression technique identified in the transmitted compression information. The customer edge router <b>110</b> attempts to use each compression technique that was identified in the transmitted compression information to decompress the packet. Whichever technique succeeds is the matched technique selected by the another customer edge router, and the customer edge router <b>110</b> has its compression signaling process <b>140</b>-<b>2</b> update the FIB table, or equivalent structure, accordingly.

In <figref idref="DRAWINGS">FIG. 6</figref>, the compression signaling process <b>140</b>-<b>2</b> repeats the same process as shown in <figref idref="DRAWINGS">FIG. 5</figref> with small variations, namely that a plurality of compression techniques are signaled through a routing protocol, and the compression signaling process <b>140</b>-<b>2</b> selects a particular technique from that plurality. Any type of selection process may be used. For example, each customer edge router <b>110</b> may store a table listing each type of compression algorithm it is programmed to use. The table may also include a ranking of those algorithm(s) according to a pre-determined priority. In one embodiment, the algorithm that has the highest priority is tried first, the algorithm with the second highest priority is tried second, and so on. Alternatively, there may be no particular priority assigned to any algorithm, and the algorithm may be selected at random. All that is required is that both the customer edge router <b>110</b> and the another customer edge router are each programmed to use that algorithm. As in <figref idref="DRAWINGS">FIG. 5</figref>, the customer edge router <b>110</b> announces, to other customer edge routers, an ability to compress packets, step <b>601</b>, through its compression signaling process <b>140</b>-<b>2</b>. The ability to compress packets is announced by adding data to a routing protocol packet, depending on the type of routing protocol being used, as described above. The customer edge router <b>110</b> then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>602</b>, through its compression signaling process <b>140</b>-<b>2</b>. As with the ability announced by the customer edge router <b>110</b>, the received announcement is also an addition to a routing protocol packet. The addition to the packet is again dependent on what type of routing protocol is being used. The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt a match with, step <b>603</b>. Here, as in <figref idref="DRAWINGS">FIG. 5</figref>, the customer edge router <b>110</b>, through its compression signaling process <b>140</b>-<b>2</b>, transmits compression information to the another customer edge router in a routing protocol packet. Unlike in <figref idref="DRAWINGS">FIG. 5</figref>, however, here the transmitted compression information identifies a plurality of compression techniques, step <b>604</b>. The another customer edge router receives the routing protocol packet, and determines that any of the plurality of compression techniques identified in the compression information of the routing protocol packet matches any compression technique the another customer edge router is programmed to use. The another customer edge router then selects a matched compression technique from any of the matched compression techniques, step <b>606</b>. In other words, the another customer edge router performs the same steps when receiving compression information signaled through a routing protocol that the customer edge router <b>110</b> performs when it receives compression information signaled through a routing protocol. As described above, the plurality of compression techniques may include any type of compression algorithm that a customer edge router, such as the customer edge router <b>110</b>, is able to use to compress (and decompress) data. Finally, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the selected matched compression technique, step <b>606</b>. The compression technique used is identified as described above with respect to step <b>506</b> of <figref idref="DRAWINGS">FIG. 5</figref>.

In <figref idref="DRAWINGS">FIGS. 7-10</figref>, the compression signaling process <b>140</b>-<b>2</b> needs to attempt another match of a compression technique that is signaled through a routing protocol used by the customer edge router. Two distinction scenarios may occur for each type of matching; that is, (1) a new match may be successful when the customer edge router <b>110</b> receives compression information, or (2) the new match may fail, and (3) a new match may be successful when the customer edge router <b>110</b> transmits compression information, or (4) that new match may fail. In the embodiments described below, the compression signaling process <b>140</b>-<b>2</b> automatically initiates a re-match if any issues arise with the current matched compression technique. In other embodiments, a user may need to take action in order for a re-match to occur. For example, a customer edge router such as the customer edge router <b>110</b> may include multiple compression techniques, as described above, and some or all of these techniques may be announced by the compression signaling process <b>140</b>-<b>2</b> upon its initiation. If all of the techniques are announced by the compression signaling process <b>140</b>-<b>2</b>, and due to any of the issues raised below, no matching compression techniques are available at any suitable other customer edge routers, a user may need to install or otherwise add one or more other compression techniques to the customer edge router <b>110</b>, or to another customer edge router. When a user does so, that customer edge router must be shut down, or otherwise taken off-line, and then re-started, or otherwise brought back on-line. Upon re-start and/or upon being brought back on-line, the compression signaling application <b>140</b>-<b>1</b> may automatically execute as the compression signaling process <b>140</b>-<b>2</b>. The compression signaling process <b>140</b>-<b>2</b> will then perform as described above, and thus may effectively re-match with another customer edge router by following the procedures described above.

<figref idref="DRAWINGS">FIG. 7</figref> addresses when the new match is successful and the customer edge router <b>110</b> receives compression information. <figref idref="DRAWINGS">FIG. 9</figref> addresses when the new match is successful and the customer edge router <b>110</b> transmits compression information. In each of these scenarios, the customer edge router <b>110</b> and compression signaling process <b>140</b>-<b>2</b> operate as described above to establish a compression technique through a signaling protocol. That is, through the compression signaling process <b>140</b>-<b>2</b>, the customer edge router <b>110</b> announces, to other customer edge routers, an ability to compress packets, step <b>701</b>/<b>901</b>. The ability to compress packets is announced by adding data to a routing protocol packet, as described above. The customer edge router <b>110</b>, through the compression signaling process <b>140</b>-<b>2</b>, then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>702</b>/<b>902</b>, which is also an addition to a routing protocol packet, such as those described above. The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt a match with, step <b>703</b>/<b>903</b>. Here, the two different processes diverge.

When the customer edge router <b>110</b> receives compression information from the another customer edge router in a routing protocol packet, step <b>704</b>, the compression signaling process <b>140</b>-<b>2</b> determines if a compression technique identified in the compression information matches any compression technique the customer edge router is programmed to use, step <b>705</b>. The compression signaling process <b>140</b>-<b>2</b> then flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the matched compression technique, step <b>706</b>. With the compression technique agreed upon, customer edge routers may transmit compressed data back and forth according to the agreed upon compression technique. At some point, however, one of the customer edge routers may no longer be able to use the matched compression technique. For example, one of the software or hardware modules that allows that customer edge router to use that compression technique may fail, or may need to be removed for repairs or an upgrade, or may simply need to be taken off-line for any reason. Alternatively, a maintainer of that customer edge router may decide to no longer provide support for that particular compression technique, for any of a number of reasons. Regardless of the particular reason, the customer edge router ceases to support that compression technique, even if for only a short amount of time. The compression signaling process <b>140</b>-<b>2</b> may determine that the customer edge router <b>110</b> is no longer able to use the match compression technique, step <b>707</b>. For example, in an embodiment where any compression technique the customer edge router <b>110</b> is programmed to use is listed in a table stored in the customer edge router <b>110</b>, if the customer edge router <b>110</b> is no longer able to use a particular technique, the entry in the table corresponding to that technique may be removed. The compression signaling process <b>140</b>-<b>2</b> may then determine that the customer edge router <b>110</b> is no longer able to use the match compression technique by accessing the table and seeing the match compression technique no longer listed. Alternatively, the compression signaling process <b>140</b>-<b>2</b> may receive communication from another process that performs the compression and decompression of data that is no longer able to do so. The process of determining is no so limited to these two examples and may include any other process of determining that a compression technique is no longer available. In response to this determination, the compression signaling process <b>140</b>-<b>2</b> sends the another customer edge router a message indicating that a change in compression techniques is needed, step <b>708</b>. The compression signaling process <b>140</b>-<b>2</b> then identifies a new matched compression technique with the another customer edge router by repeating the step of matching, step <b>709</b>. Upon a successful new match being identified, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router to be compressed and decompressed according to the identified new matched compression technique, step <b>710</b>.

Alternatively, when the customer edge router <b>110</b> transmits compression information in a routing protocol packet, step <b>904</b>, the compression information identifies a compression technique. The another customer edge router receives the routing protocol packet and determines that a compression technique identified in the compression information of the routing protocol packet matches any compression technique the another customer edge router is programmed to use. The compression signaling process <b>140</b>-<b>2</b> then flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the matched compression technique, step <b>906</b>. Then, for any of the reasons described above or any other reason(s), the matched compression technique may no longer be usable by the another customer edge router. The customer edge router <b>110</b> then receives a message from the another customer edge router indicating that a change in compression techniques is needed, step <b>908</b>. The compression signaling process <b>140</b>-<b>2</b> then identifies a new matched compression technique with the another customer edge router by repeating the step of matching, step <b>909</b>. Upon a successful new match being identified, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router to be compressed and decompressed according to the identified new matched compression technique, step <b>910</b>.

The above two scenarios presume that the next attempt at matching is successful. It is possible that the matching attempt will not succeed, however. For example, if the customer edge router no longer supports any type of compression technique, there is no way for the compression signaling process <b>140</b>-<b>2</b> to match a compression technique. Alternatively, if the customer edge routers no longer both support at least one of the same techniques, there is no way for the compression signaling process <b>140</b>-<b>2</b> to match a compression technique. It is still possible to maintain compressed transmissions between the networks of which the customer edge routers are a part, as is shown in <figref idref="DRAWINGS">FIG. 8</figref> (where the customer edge router <b>110</b> receives compression information) and <b>10</b> (where the customer edge router <b>110</b> transmits compression information).

First, steps <b>801</b>-<b>810</b>, which correspond to steps <b>701</b>-<b>710</b> described above, and steps <b>1001</b>-<b>1010</b>, which correspond to steps <b>901</b>-<b>910</b> described above, are repeated. If the attempt at a new match fails, that is, the compression signaling processes <b>140</b>-<b>2</b> fail to identify a new matching compression technique, step <b>811</b>/<b>1011</b>, in response, the compression signaling process <b>140</b>-<b>2</b> locates a second customer edge router with an announced capability to compress packets from another customer edge router in the network, wherein the second customer edge router and the another customer edge router are connected to the same local network, step <b>812</b>/<b>1012</b>. The compression signaling process <b>140</b>-<b>2</b> would then conduct a new matching with the second customer edge router by repeating the step of negotiating, step <b>813</b>/<b>1013</b>. Finally, the compression signaling process <b>140</b>-<b>2</b> would flag packets transmitted from and received by the customer edge router to be compressed and decompressed according to the matched compression technique, step <b>814</b>/<b>1014</b>. As soon as this is completed, transmission of compressed data between the networks may resume over the customer edge routers involved in the new matching.

In <figref idref="DRAWINGS">FIG. 11</figref>, the compression signaling process <b>140</b>-<b>2</b> must address a situation where the routing protocol used between provider edge routers differs from the routing protocol used between a customer edge router and a provider edge router. Thus, as described above in connection with <figref idref="DRAWINGS">FIG. 2</figref>, the customer edge router communicates with other customer edge routers through a provider edge router and a provider network.

Through the compression signaling process <b>140</b>-<b>2</b>, the customer edge router <b>110</b> announces, to other customer edge routers, an ability to compress packets, step <b>1101</b>. The customer edge router <b>110</b>, through the compression signaling process <b>140</b>-<b>2</b>, then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>1102</b>. The ability to compress packets is announced by adding data to a routing protocol packet, as described above.

The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt a match with, step <b>1103</b>. The customer edge router <b>110</b> receives compression information from the another customer edge router in a routing protocol packet, step <b>1104</b>, and then the compression signaling process <b>140</b>-<b>2</b> determines that a compression technique identified in the compression information matches any compression technique the customer edge router is programmed to use, step <b>1104</b>. (Of course, this same process may be repeated when the compression signaling process <b>140</b>-<b>2</b> transmits compression information instead of receiving it.) As described above, the compression technique may be any type of compression algorithm that a customer edge router, such as the customer edge router <b>110</b>, is able to use to compress (and decompress) data. The compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router <b>110</b> to be compressed and decompressed according to the matched compression technique, step <b>1106</b>.

The compression signaling process <b>140</b>-<b>2</b> may then detect a customer edge-provider edge routing protocol used for transmissions between the customer edge router and a corresponding provider edge router, step <b>1107</b>. If the customer edge-provider edge routing protocol detected by the compression signaling process <b>140</b>-<b>2</b> differs from a provider edge-provider edge routing protocol used for transmissions between provider edge routers, the compression signaling process <b>140</b>-<b>2</b> performs two steps for each customer edge router involved, step <b>1108</b>. First, the compression signaling process <b>140</b>-<b>2</b> extends any compression information from the customer edge-provider edge routing protocol for use by the provider edge-provider edge routing protocol. Second, the compression signaling process <b>140</b>-<b>2</b> extracts any compression information from the provider edge-provider edge routing protocol for use by the customer edge-provider edge routing protocol. This allows the functionality of the compression signaling process <b>140</b>-<b>2</b> to be extended regardless of the type of protocol used for transmissions between provider edge routers.

In <figref idref="DRAWINGS">FIG. 12</figref>, the customer edge routers perform compression only on a class of packets that is identified through a routing protocol by the compression signaling process <b>140</b>-<b>2</b>. A class of packets is a grouping of packets according to one or more particular characteristics. For example, a class of packets may be defined to include all packets that originated from a particular network address. In another example, a class of packets may be defined to include all packets that contain data of a particular type, such as audio or video data. Through the compression signaling process <b>140</b>-<b>2</b>, the customer edge router <b>110</b> announces, to other customer edge routers, an ability to compress packets, step <b>1201</b>. The ability to compress packets is announced by adding data to a routing protocol packet, as described above. The customer edge router <b>110</b>, through the compression signaling process <b>140</b>-<b>2</b>, then receives an announcement of an ability to compress packets from another customer edge router in the network, step <b>1202</b>. As with the ability announced by the customer edge router <b>110</b>, the received announcement is also an addition to a routing protocol packet, such as those described above.

The compression signaling process <b>140</b>-<b>2</b> next matches a compression technique with whatever another customer edge router the customer edge router <b>110</b> decides to attempt a match with, step <b>1203</b>. The customer edge router <b>110</b> receives compression information from the another customer edge router in a routing protocol packet, step <b>1204</b>, and the compression signaling process <b>140</b>-<b>2</b> determines if a compression technique identified in the compression information matches any compression technique the customer edge router is programmed to use, step <b>1205</b>. (Of course, this process may be repeated when the compression signaling process <b>140</b>-<b>2</b> transmits compression information instead of receives it.) Then, the compression signaling process <b>140</b>-<b>2</b> flags packets transmitted from and received by the customer edge router, that are also in the identified class of packets, to be compressed and decompressed according to the matched compression technique, step <b>1207</b>.

Note that, in regards to the usage of OSPF described herein, an alternative is to have the compression signaling process <b>140</b>-<b>2</b> use a Link-Scope Opaque link-state advertisement (LSA) to carry the CAS-TLV. The remaining usage is otherwise unchanged. Note further that a very similar protocol extension may be made to other Interior Gateway Protocols (IGPs), such as Intermediate System-Intermediate System (ISIS) and Enhanced Interior Gateway Routing Protocol (EIGRP).

The methods and systems described herein are not limited to a particular hardware or software configuration, and may find applicability in many computing or processing environments. The methods and systems may be implemented in hardware or software, or a combination of hardware and software. The methods and systems may be implemented in one or more computer programs, where a computer program may be understood to include one or more processor executable instructions. The computer program(s) may execute on one or more programmable processors, and may be stored on one or more storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), one or more input devices, and/or one or more output devices. The processor thus may access one or more input devices to obtain input data, and may access one or more output devices to communicate output data. The input and/or output devices may include one or more of the following: Random Access Memory (RAM), Redundant Array of Independent Disks (RAID), floppy drive, CD, DVD, magnetic disk, internal hard drive, external hard drive, memory stick, or other storage device capable of being accessed by a processor as provided herein, where such aforementioned examples are not exhaustive, and are for illustration and not limitation.

The computer program(s) may be implemented using one or more high level procedural or object-oriented programming languages to communicate with a computer system; however, the program(s) may be implemented in assembly or machine language, if desired. The language may be compiled or interpreted.

As provided herein, the processor(s) may thus be embedded in one or more devices that may be operated independently or together in a networked environment, where the network may include, for example, a Local Area Network (LAN), wide area network (WAN), and/or may include an intranet and/or the internet and/or another network. The network(s) may be wired or wireless or a combination thereof and may use one or more communications protocols to facilitate communications between the different processors. The processors may be configured for distributed processing and may utilize, in some embodiments, a client-server model as needed. Accordingly, the methods and systems may utilize multiple processors and/or processor devices, and the processor instructions may be divided amongst such single- or multiple-processor/devices.

The device(s) or computer systems that integrate with the processor(s) may include, for example, a personal computer(s), workstation(s) (e.g., Sun, HP), personal digital assistant(s) (PDA(s)), handheld device(s) such as cellular telephone(s), laptop(s), handheld computer(s), or another device(s) capable of being integrated with a processor(s) that may operate as provided herein. Accordingly, the devices provided herein are not exhaustive and are provided for illustration and not limitation.

References to “a microprocessor” and “a processor”, or “the microprocessor” and “the processor,” may be understood to include one or more microprocessors that may communicate in a stand-alone and/or a distributed environment(s), and may thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor may be configured to operate on one or more processor-controlled devices that may be similar or different devices. Use of such “microprocessor” or “processor” terminology may thus also be understood to include a central processing unit, an arithmetic logic unit, an application-specific integrated circuit (IC), and/or a task engine, with such examples provided for illustration and not limitation.

Furthermore, references to memory, unless otherwise specified, may include one or more processor-readable and accessible memory elements and/or components that may be internal to the processor-controlled device, external to the processor-controlled device, and/or may be accessed via a wired or wireless network using a variety of communications protocols, and unless otherwise specified, may be arranged to include a combination of external and internal memory devices, where such memory may be contiguous and/or partitioned based on the application. Accordingly, references to a database may be understood to include one or more memory associations, where such references may include commercially available database products (e.g., SQL, Informix, Oracle) and also proprietary databases, and may also include other structures for associating memory such as links, queues, graphs, trees, with such structures provided for illustration and not limitation.

References to a network, unless provided otherwise, may include one or more intranets and/or the internet. References herein to microprocessor instructions or microprocessor-executable instructions, in accordance with the above, may be understood to include programmable hardware.

Unless otherwise stated, use of the word “substantially” may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems.

Throughout the entirety of the present disclosure, use of the articles “a” or “an” to modify a noun may be understood to be used for convenience and to include one, or more than one of the modified noun, unless otherwise specifically stated.

Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein.

Although the methods and systems have been described relative to a specific embodiment thereof, they are not so limited. Obviously many modifications and variations may become apparent in light of the above teachings. Many additional changes in the details, materials, and arrangement of parts, herein described and illustrated, may be made by those skilled in the art.